As connection line speeds increase, to rates as high as five (5) to ten (10) Gigabits per second (Gb/s), and beyond, active optical cables (AOCs) are increasingly being used as an alternative to traditional copper cables. Active optical cables allow electrical signals to be converted and carried as optical signals over optical fiber. Benefits of utilizing optical fiber include extremely wide bandwidth and high immunity to environmental electronic noise. There also may be a power consumption advantage to using active optical cables for connecting electrical devices across distances greater than ten (10) meters because the power required by the active optical cables to convert the signals between the electrical and optical domains is less than the power consumption required to transmit high bandwidth data with copper cables.
In this regard, FIG. 1 illustrates an exemplary active optical cable 10 including end connectors 12A, 12B. Each end connector 12A, 12B may include electrical conductor inputs 14A configured to receive input electrical signals and electrical conductor outputs 14B configured to provide output electrical signals. Opto-electronic transceivers 16A, 16B may be included within end connector housings 18A, 18B for each of the end connectors 12A, 12B, respectively. The opto-electronic transceivers 16A, 16B each may include transmitter optical sub-assemblies (TOSAs) (not shown) that receive electrical input signals from the electrical conductor inputs 14A and convert the received electrical input signals into optical signals to be transmitted over optical fiber 15. The opto-electronic transceivers 16A, 16B may also each include receiver optical sub-assemblies (ROSAs) (not shown) that convert the optical signals transmitted over the optical fiber 15 back into electrical signals to be provided as electrical output signals on the electrical conductor outputs 14B.
Although active optical cabling is available, copper twisted pair cabling (“copper cables”), for example Category 5 cables or Category 6 cables have been commonly used to provide interconnections between electrical devices within buildings, campuses, and facilities where distances are short enough to facilitate low frequency communications. Copper twisted pair cabling becomes less attractive when used for higher signal frequencies and longer cable distances because of the impedance of the cable, which increases with distance. However, through the use of mid-span electrical amplifiers and repeaters, copper twisted pair cables may provide reliable interconnectibility options between electrical devices for accurate signal transfer.
As the reliability of copper twisted pair cabling is well-known and is widely used, significant infrastructure investments have been made, for example, to develop, procure and install complex copper-based switching devices capable of interconnecting a wide range of electrical devices in interconnection configurations. Electrical interfaces including power and electrical signal capability compatible with standard protocols, for example, HDMI, are well-established and have been adapted to the interconnection configurations which may be used in data centers to deliver voice, video, and data transmissions to subscribers over both private and public networks. For example, active optical cables can support connections between servers, storage area networks (SANs), and/or other equipment in data centers.
As the demand for bandwidth to interconnect devices increases at or above 10 Gb/s, for cable distances spanning more than ten (10) meters there is a need to reduce power consumption by avoiding electrical amplifiers or repeaters which are normally used in copper cables. As the majority of the electrical devices have electrical interfaces to be compatible with copper cables and the electrical devices are expensive to replace, any new interconnection installations need to be compatible with the electrical interfaces of the existing electrical devices. Active optical cables fulfill the power consumption and interface compatibility requirements needed for interconnectability of electrical devices but currently lack the ability to form complex interconnection configurations as are currently possible with copper cables. Active optical cables would also need to be flexible so as to support the required connectivity even though the electrical devices may be replaced by upgraded equipment over time.
What is needed is a system or method to connect electrical devices in a highly-configurable manner so that the interconnection and transmission of the electrical signals among those electrical devices can accommodate the high bandwidth and lower power consumption requirements of the electrical devices.